This inexpensive H531 level meter does not have data storage and therefore cannot function as a data logger. Measured values are displayed on a graphic display, which informs the operator of changes in the level over time; the display interval is adjustable from a few hours to several weeks.
To conserve battery power, the device’s display is turned off and turns on briefly only when one of the control buttons is pressed. The device also includes a binary output for controlling an external relay based on the set level limits. Parameterization is performed using the buttons and the display.
The level meter’s electronic circuitry allows for the connection of a standard level sensor with a 4–20 mA output in addition to the low-cost TSH27 sensor. This capability extends the level meter’s application to measurement ranges not covered by the TSH27 sensor.
Since the level meter is primarily battery-powered, it does not require an external power supply to operate. However, external power can be supplied to the device, which allows not only continuous measurement but also the backlit graphic display to remain on at all times.